# CARD_WriteEepromAsync

## C Specification

      #include <nitro/card.h>

      static inline void CARD_WriteEepromAsync(
          u32              dst,
          const void      *src,
          u32              len,
          MIDmaCallback    callback,
          void             *arg);

## Description

Writes data asynchronously to an EEPROM device.

Before using this function, you must lock the access bus using the `CARD_LockBackup` function.

Use the `CARD_WaitBackupAsync` function to wait for the process to complete. To determine the result when complete, call the `CARD_GetResultCode` function.

This function returns control promptly.

This function performs communications internally with the I/O processor through PXI. Be aware that the process will not complete if the PXI interrupt is not valid.

## Internal Operation

This function uses an internal thread to process data asynchronously. See the description of the `CARD_GetThreadPriority` function for information about this thread.

## Arguments

`dst` | Transfer destination EEPROM address
`src` | Transfer source memory address
`len` | Length of write data (in bytes)
`callback` | Callback function upon completion. Specify NULL when not needed.
`arg` | Argument passed to callback function upon completion. Ignored when the callback specifies NULL.

## Return Values

None.

## See Also

`CARD_IsBackupEeprom`, `CARD_WaitBackupAsync`, `CARD_GetResultCode`, `CARD_ReadEeprom`, `CARD_WriteEeprom`, `CARD_VerifyEeprom`, `CARD_WriteAndVerifyEeprom`, `CARD_GetThreadPriority`

## Revision History

11/02/2004 Corrected a link.
08/18/2004 Added description about the PXI interrupt.
07/28/2004 Initial version.